1. Field of the Invention
The present invention relates to a sealing device and more particularly to a sealing device adapted for use on a fluid system, such as that having sprinklers, to permit flushing of debris from the system and being operable to prevent such matter from reentering the system after such flushing has been completed.
2. Description of the Prior Art
There are a variety of environments in which the initial installation and operation of a fluid system necessitates clearing or flushing of the system prior to it being placed in a fully operative condition. For example, in the installation of sprinkler systems such as used for irrigation, the systems must be vented prior to installation of the sprinkler nozzles thereof to discharge matter such as dirt, sand, metal or plastic particles, pipe sealing compounds and adhesive fragments. If this is not done prior to installation of the nozzles, such matter can become lodged in the orifices thereof during initial pressurization of the system. Where this occurs, the obstructed nozzles must be removed, the matter dislodged from the orifices or the nozzles replaced, and the sprinkler system again vented of such matter.
The process of removing or replacing sprinkler nozzles in the installation of sprinkler systems is not only tedious and time consuming, but is expensive in the manual labor required therefor and in the cost of the replacement nozzles. Furthermore, particularly in commercial installations where large numbers of sprinkler nozzles may be involved, the cleaning or replacement of such nozzles is typically incompletely or inadequately performed to the extent that the sprinkler system is to that extent ineffectual.
Because of these difficulties, it has been known in the industry to use shipping caps which are installed on sprinklers at the time of manufacture in place of the nozzles permitting the sprinkler system to be vented for the discharge of such debris prior to installation of the nozzles. This has the additional benefit of sealing the interior of the sprinkler during shipping and installation and permitting any desired nozzle to be installed in the sprinkler after installation. For example, the Groendyke U.S. Pat. No. 4,752,033 shows one such cap intended for this purpose.
However, all such prior art shipping caps have been ineffectual to one degree or another in that no positive seal is formed preventing matter from flowing back into the sprinkler once the flushing operation has been performed. Thus, even though such prior art shipping caps have assisted to a degree in accomplishing the stated objectives, they have not completely occluded the sprinkler against an influx of such matter and, accordingly, have been less than satisfactory for the intended purpose.
Therefore, it has long been known that it would be desirable to have a sealing device adapted to cooperate with the normal operation of a sprinkler to seal the interior thereof when the sprinkler is at or near an unpressurized condition; which permits flushing of deleterious matter from the interior of the sprinkler during installation without the concomitant hazard of such matter being drawn back into the interior of the sprinkler upon depressurization of the system; is operable to facilitate removal thereof for replacement with a sprinkler nozzle subsequent to the flushing operation; and which is both practical and inexpensive as well as fully dependable in achieving its intended objectives.